The invention relates generally to modular conveyors, belts and chains and, more particularly, to such conveyors, belts and chains which include side-flexing capability, i.e., the ability to turn left or right in the plane of conveyor movement.
In the past, side-flexing conveyors were limited in width and some of such prior side-flexing conveyors transferred the load in tension in the direction of intended conveyor travel only at the middle of the chain conveyor. Such conveyors undesireably experienced very heavy loading at the middle portion of the chain. Other prior side-flexing conveyors depended on the pins to carry the load from link to link, thereby placing a high shear load on the pins, and particularly at the ends thereof during side-flexing operation.
Previous designs for side flexing modular belting or chain involved simply forming slotted holes where the pin joins the links to allow side-flexure of the links in the direction of travel. These previous designs have several limitations. The first limitation is that, because of the slotted holes, the belt or chain can expand and compress. This elasticity requires tension to always be placed on the modular belting for proper running i.e., the belting was always preloaded for proper functionality.
The second limitation is inherent in the prior designs and results in carrying of the entire load, when the chain is side-flexing, at the sides of the chain. Thus, the outer portion of the pin carries the entire load in side-flexure because the pin only contacts the links at that point.
Attention is directed to the following U.S. Patents:
U.S. Pat. No. 3,261,451, G. C. Roinestad, Jul. 19, 1966 PA1 U.S. Pat. No. 3,826,150, K. V. Palmaer, Jul. 30, 1974 PA1 U.S. Pat. No. 3,854,575, Fraioli, Sr., Dec. 17, 1974 PA1 U.S. Pat. No. 3,946,857, Fraioli, Sr., Mar. 30, 1976 PA1 U.S. Pat. No. 4,185,737, K. Blattermann, Jan. 29,1980 PA1 U.S. Pat. No. 4,222,483, Wootton et al., Sep. 16, 1980 PA1 U.S. Pat. No. 4,276,980, Y. Oizumi, Jul. 7, 1981 PA1 U.S. Pat. No. 4,640,410, Palmaer et al., Feb. 3, 1987 PA1 U.S. Pat. No. 4,742,907, K. V. Palmaer, May 10, 1988 PA1 U.S. Pat. No. 4,846,339, G. Roinestad, Jul. 11, 1989 PA1 U.S. Pat. No. 4,901,844, Palmaer et al., Feb. 20, 1990 PA1 U.S. Pat. No. 4,934,517, J. M. Lapeyre, Jun. 19, 1990 PA1 U.S. Pat. No. 5,181,601, Palmaer et al., Jan. 26, 1993 PA1 U.S. Pat. No. 5,224,583, Palmaer et al., Jul. 6, 1993 PA1 U.S. Pat. No. 5,310,046, Palmaer et al., May 10, 1994 PA1 U.S. Pat. No. 5,372,248, P. L. Horton, Dec. 13, 1994 PA1 0427337, EP, May 15, 1991 PA1 1,312,301, Canada, May 1, 1993
Attention is also directed to the following foreign patents: